On Wed, Apr 23, 2025 at 07:04:16PM -0700, Abhinav Kumar wrote:
>
>
> On 2/26/2025 6:25 PM, Dmitry Baryshkov wrote:
> > LVDS support in MDP4 driver makes use of drm_connector directly. However
> > LCDC encoder and LVDS connector are wrappers around drm_panel. Switch
> > them to use drm_panel_bridge/drm_bridge_connector. This allows using
> > standard interface for the drm_panel and also inserting additional
> > bridges between encoder and panel.
> >
> > Signed-off-by: Dmitry Baryshkov <dmitry.barysh...@linaro.org>
> > ---
> > drivers/gpu/drm/msm/Makefile | 1 -
> > drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c | 34 +++++--
> > drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h | 6 +-
> > drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c | 20 +----
> > .../gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 100
> > ---------------------
> > 5 files changed, 28 insertions(+), 133 deletions(-)
> >
> > @@ -199,27 +201,43 @@ static int mdp4_modeset_init_intf(struct mdp4_kms
> > *mdp4_kms,
> > * bail out early if there is no panel node (no need to
> > * initialize LCDC encoder and LVDS connector)
> > */
> > - panel_node = of_graph_get_remote_node(dev->dev->of_node, 0, 0);
> > - if (!panel_node)
> > - return 0;
> > + next_bridge = devm_drm_of_get_bridge(dev->dev,
> > dev->dev->of_node, 0, 0);
> > + if (IS_ERR(next_bridge)) {
> > + ret = PTR_ERR(next_bridge);
> > + if (ret == -ENODEV)
> > + return 0;
> > + return ret;
> > + }
> > - encoder = mdp4_lcdc_encoder_init(dev, panel_node);
> > + encoder = mdp4_lcdc_encoder_init(dev);
> > if (IS_ERR(encoder)) {
> > DRM_DEV_ERROR(dev->dev, "failed to construct LCDC
> > encoder\n");
> > - of_node_put(panel_node);
> > return PTR_ERR(encoder);
> > }
> > /* LCDC can be hooked to DMA_P (TODO: Add DMA_S later?) */
> > encoder->possible_crtcs = 1 << DMA_P;
> > - connector = mdp4_lvds_connector_init(dev, panel_node, encoder);
> > + ret = drm_bridge_attach(encoder, next_bridge, NULL,
> > DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> > + if (ret) {
> > + DRM_DEV_ERROR(dev->dev, "failed to attach LVDS
> > panel/bridge: %d\n", ret);
> > +
> > + return ret;
> > + }
>
> Can you pls point me to the lvds bridge used with this apq8064 board? I was
> unable to find it. Just wanted to compare that against this while reviewing.
It's the panel bridge, wrapping one of the LVDS panels.
> > +
> > + connector = drm_bridge_connector_init(dev, encoder);
> > if (IS_ERR(connector)) {
> > DRM_DEV_ERROR(dev->dev, "failed to initialize LVDS
> > connector\n");
> > - of_node_put(panel_node);
> > return PTR_ERR(connector);
> > }
> > + ret = drm_connector_attach_encoder(connector, encoder);
> > + if (ret) {
> > + DRM_DEV_ERROR(dev->dev, "failed to attach LVDS
> > connector: %d\n", ret);
> > +
> > + return ret;
> > + }
> > +
> > break;
> > case DRM_MODE_ENCODER_TMDS:
> > encoder = mdp4_dtv_encoder_init(dev);
--
With best wishes
Dmitry
